US10488708B2 - Backlight module - Google Patents
Backlight module Download PDFInfo
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- US10488708B2 US10488708B2 US16/013,958 US201816013958A US10488708B2 US 10488708 B2 US10488708 B2 US 10488708B2 US 201816013958 A US201816013958 A US 201816013958A US 10488708 B2 US10488708 B2 US 10488708B2
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- light output
- light
- backlight module
- prism sheet
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- G—PHYSICS
- G02—OPTICS
- G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
- G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour
- G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour based on liquid crystals, e.g. single liquid crystal display cells
- G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
- G02F1/1333—Constructional arrangements; Manufacturing methods
- G02F1/1335—Structural association of cells with optical devices, e.g. polarisers or reflectors
- G02F1/1336—Illuminating devices
- G02F1/133602—Direct backlight
- G02F1/133606—Direct backlight including a specially adapted diffusing, scattering or light controlling members
-
- G—PHYSICS
- G02—OPTICS
- G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
- G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour
- G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour based on liquid crystals, e.g. single liquid crystal display cells
- G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
- G02F1/1333—Constructional arrangements; Manufacturing methods
- G02F1/1335—Structural association of cells with optical devices, e.g. polarisers or reflectors
- G02F1/1336—Illuminating devices
- G02F1/133615—Edge-illuminating devices, i.e. illuminating from the side
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B5/00—Optical elements other than lenses
- G02B5/04—Prisms
- G02B5/045—Prism arrays
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- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
- G02B6/0001—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems
- G02B6/0011—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems the light guides being planar or of plate-like form
- G02B6/0013—Means for improving the coupling-in of light from the light source into the light guide
- G02B6/0023—Means for improving the coupling-in of light from the light source into the light guide provided by one optical element, or plurality thereof, placed between the light guide and the light source, or around the light source
- G02B6/0025—Diffusing sheet or layer; Prismatic sheet or layer
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
- G02B6/0001—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems
- G02B6/0011—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems the light guides being planar or of plate-like form
- G02B6/0033—Means for improving the coupling-out of light from the light guide
- G02B6/005—Means for improving the coupling-out of light from the light guide provided by one optical element, or plurality thereof, placed on the light output side of the light guide
- G02B6/0053—Prismatic sheet or layer; Brightness enhancement element, sheet or layer
-
- G—PHYSICS
- G02—OPTICS
- G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
- G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour
- G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour based on liquid crystals, e.g. single liquid crystal display cells
- G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
- G02F1/1333—Constructional arrangements; Manufacturing methods
- G02F1/1335—Structural association of cells with optical devices, e.g. polarisers or reflectors
- G02F1/1336—Illuminating devices
- G02F1/133602—Direct backlight
- G02F1/133606—Direct backlight including a specially adapted diffusing, scattering or light controlling members
- G02F1/133607—Direct backlight including a specially adapted diffusing, scattering or light controlling members the light controlling member including light directing or refracting elements, e.g. prisms or lenses
-
- G02F2001/133607—
-
- G—PHYSICS
- G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
- G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
- G09G2320/00—Control of display operating conditions
- G09G2320/02—Improving the quality of display appearance
- G09G2320/0233—Improving the luminance or brightness uniformity across the screen
Definitions
- the invention relates to a backlight module, and more particularly to a backlight module capable of providing better optical quality.
- LCDs liquid crystal displays
- the LCDs Due to the advantageous features of the LCDs, for example, high space utilization efficiency, low power consumption, free radiation, and low electrical field interference, the LCDs have become the main stream in the market. It is commonly known that the LCD includes an LCD panel and a backlight module, and because the LCD panel cannot emit light by itself, it is necessary to dispose the backlight module below the LCD panel to provide a surface light source required by the LCD panel. As a result, the LCD may display an image for viewers.
- the emitted light at full width at half maximum (FWHM) is within 40 degrees, which is used as the basis for collimated light output.
- the reverse prism may be used to achieve the aforementioned requirements.
- the reverse prism is expensive.
- the shielding property of a single reverse prism is low. Therefore, if there are any defects (such as scratches) on the light output surface or the reverse prism of the light output module, it is easy to cause the bias of the light path, which is easily seen. Therefore, the yield rate of producing the reverse prism used in the backlight module is low.
- the problem is that how to use other optical films to adjust the FWHM of the emitted light, so as to improve the collimated light pattern of the backlight module and to reduce light at large viewing angle. Moreover, how to generate the halo effect when local dimming is reduced, so as to enhance visual effect and meet the demand for high-collimated backlight module is a urgent topic need to be solved recently.
- the invention provides a backlight module capable of improving color shift and providing an uniform light color.
- a backlight module of the invention includes a light output module, a first prism sheet, and a second prism sheet.
- the light output module has a light output surface.
- the first prism sheet is disposed on the light output surface of the light output module.
- the first prism sheet has a plurality of first prism structures extending in a first extending direction.
- the second prism sheet is disposed on the first prism sheet.
- the second prism sheet has a plurality of second prism structures extending in a second extending direction. The angle between the first extending direction and the second extending direction is less than or equal to 30 degrees.
- the first prism sheet has a plurality of first prism structures extending in the first extending direction
- the second prism sheet has a plurality of second prism structures extending in the second extending direction
- the angle between the first extending direction and the second extending direction is less than or equal to 30 degrees. Since the first prism sheet and the second prism sheet provide some optical effects, such as refraction, reflection, scattering and/or diffraction, etc., the emitted light is focused within a certain range of viewing angle, so that the light emitted by the backlight module is focused in order to increase the overall brightness and uniformity of the backlight module and to enhance the brightness. Therefore, the backlight module constituted by the light output module, the first prism sheet and the second prism sheet can reduce light at large viewing angle and can improve the collimation of light.
- FIG. 1A to FIG. 1B are partial and three dimensional exploded views of a backlight module according to the first embodiment of the invention.
- FIG. 1C is a three dimensional exploded view of the backlight module according to the first embodiment of the invention.
- FIG. 2A to FIG. 2B are schematic top views of a part of the backlight module according to the first embodiment of the invention.
- FIG. 2C is a schematic top view of the backlight module according to the first embodiment of the invention.
- FIG. 3A is a cross-sectional schematic view of a part of the backlight module according to the first embodiment of the invention.
- FIG. 3B is a cross-sectional schematic view of another part of the backlight module according to the first embodiment of the invention.
- FIG. 3C is a cross-sectional schematic view of yet another part of the backlight module according to the first embodiment of the invention.
- FIG. 4 is a cross-sectional schematic view of a backlight module according to the second embodiment of the invention.
- FIG. 5 is a cross-sectional schematic view of a backlight module according to the third embodiment of the invention.
- FIG. 6 is a schematic view of a backlight module according to the fourth embodiment of the invention.
- FIG. 7 is a three dimensional exploded view of a backlight module according to the fifth embodiment of the invention.
- FIG. 8 is a three dimensional exploded view of a backlight module according to the sixth embodiment of the invention.
- FIG. 9 is a schematic view illustrating coordinate in an exemplary experiment of the invention.
- FIG. 10A to FIG. 10C are diagrams showing a relationship of light intensities in different visual directions of an exemplary experiment 1 of the invention.
- FIG. 11A to FIG. 11C are diagrams showing a relationship of light intensities in different visual directions of an exemplary experiment 2 of the invention.
- the included angle between two directions can be derived by using general mathematics (such as Cosine Rule). Therefore, in this description, it does not restrict that an included angle formed by two directions must be an included angle having a cross point.
- a straight line corresponding to an extending direction and another straight line corresponding to another extending direction are essentially skew lines that do not intersect and are not parallel with each other, but the extending direction and the another extending direction may also have an included angle derived according to a general mathematics.
- an included angle between a direction and a plane usually refers to the complementary angle formed by the direction and the normal vector of the plane and can also be derived by using general mathematics.
- the numerical value recited in this description may present that numerical value and the deviation value within the acceptable range known by person of ordinary skill in the art.
- the deviation value may be one or more standard deviations in the manufacturing process or measuring process, or may be the calculation error caused by some factors, such as the number of digits used in the calculation or conversion process, rounding number up or down, unit conversion, or error propagation, etc.
- FIG. 1A to FIG. 1B are partial and three dimensional exploded views of a backlight module according to the first embodiment of the invention.
- FIG. 1C is a three dimensional exploded view of the backlight module according to the first embodiment of the invention.
- FIG. 2A to FIG. 2B are schematic top views of a part of the backlight module according to the first embodiment of the invention.
- FIG. 2C is a schematic top view of the backlight module according to the first embodiment of the invention.
- FIG. 3A is a cross-sectional schematic view of another part of the backlight module according to the first embodiment of the invention.
- FIG. 3B is a cross-sectional schematic view of another part of the backlight module according to the first embodiment of the invention.
- FIG. 3C is a cross-sectional schematic view of yet another part of the backlight module according to the first embodiment of the invention.
- FIG. 1A are partial and three dimensional exploded views of a light output module 110 of a backlight module 100 according to the first embodiment of the invention.
- FIG. 2A is a schematic top view of FIG. 1A .
- FIG. 1B is three dimensional exploded view of a light emitting module 120 , a light guide plate 130 , and a first prism sheet 150 of the backlight module 100 according to the first embodiment of the invention.
- FIG. 2B is a schematic top view of FIG. 1B .
- FIG. 2C is a schematic top view of FIG. 1C .
- FIG. 1A are partial and three dimensional exploded views of a light output module 110 of a backlight module 100 according to the first embodiment of the invention.
- FIG. 2A is a schematic top view of FIG. 1A .
- FIG. 1B is three dimensional exploded view of a light
- FIG. 3A is a cross-sectional schematic view of the light output module 110 of the backlight module 100 according to the first embodiment of the invention.
- FIG. 3B is a cross-sectional schematic view of the first prism sheet 150 of the backlight module 100 according to the first embodiment of the invention.
- FIG. 3C is a cross-sectional schematic view of a second prism sheet 170 of the backlight module 100 according to the first embodiment of the invention. Additionally, in FIG. 2B and FIG. 2C , the local high point position of the first prism sheet 150 and the second prism sheet 170 is represented by a dash line, and the local low point position of the first prism sheet 150 and the second prism sheet 170 is represented by a dash-dot line.
- the backlight module 100 includes the light output module 110 , the first prism sheet 150 , and the second prism sheet 170 , and the light output module 110 may include the light emitting module 120 , the light guide plate 130 , and a reflective sheet 140 .
- the light emitting module 120 may be a light bar, for example.
- the light L 0 generated by the light emitting module 120 after entering a light incident surface 130 c of the light guide plate 130 , is reflected by the reflective sheet 140 and then be guided to a top surface 130 a of the light guide plate 130 , so as to form a light L 1 emitted from a light output surface 110 a of the light output module 110 .
- the backlight module 100 may be an edge lighting type backlight module, but the invention is not limited thereto. In other embodiments, the backlight module 100 may be a bottom lighting type backlight module.
- the light guide plate 130 has the top surface 130 a , a bottom surface 130 b , and the light incident surface 130 c .
- the top surface 130 a and the bottom surface 130 b are opposite each other, and the top surface 130 a is substantially perpendicular to the light incident surface 130 c .
- the light emitting module 120 is diposed corresponding to the light incident surface 130 c of the light guide plate 130
- the reflective sheet 140 is disposed corresponding to the bottom surface 130 b of the light guide plate 130 , and in the normal direction (such as z direction) of the top surface 130 a , the distance between the top surface 130 a and the bottom surface 130 b is constant.
- the light guide plate 130 is a flat-type light guide plate, for example, and essentially, the top surface 130 a of the light guide plate 130 may be the light output surface 110 a of the light output module 110 , but the invention is not limited thereto. In other embodiments, the light guide plate 130 may also be a wedge-shaped light guide plate.
- the light L 1 emitted from the light output module 110 has a first maximum brightness in a first light output direction L 1 a
- the light L 1 emitted from the light output module 110 has a second maximum brightness in a second light output direction L 1 b
- the second maximum brightness is half of the first maximum brightness
- an included angle A 1 between the first light output direction L 1 a and a normal direction 110 n of the light output surface 110 a is equal to an included angle A 2 between the second light output direction L 1 b and the normal direction 110 n of the light output surface 110 a
- the second light output direction L 1 b may be the light L 1 in a direction that the light L 1 has a FWHM in brightness.
- the included angle A 1 between the first light output direction L 1 a and the normal direction 110 n of the light output surface 110 a is greater than or equal to 60 degrees, and an included angle A 3 between the second light output direction L 1 b and the first light output direction L 1 a is smaller than or equal to 15 degrees, but the invention is not limited thereto.
- the first prism sheet 150 is disposed on the light output surface 110 a of the light output module 110 .
- the first prism sheet 150 has a plurality of first prism structures 151 extending in a first extending direction 151 a , and the first prism structures 151 facing away from the light output module 110 . More specifically, the first prism sheet 150 has a first surface 150 a and a second surface 150 b opposite to the first surface 150 a , the first prism structures 151 is located on the first surface 150 a , and the second surface 150 b faces the light output surface 110 a of the light output module 110 . Simply, the first prism sheet 150 is not a reverse prism sheet.
- the light L 1 After entering from the second surface 150 b of the first prism sheet 150 , the light L 1 , which is emitted from the light output surface 110 a of the light output module 110 , may have changes of the light path within the first slice 150 (such as refraction and/or reflection), so as to form a light L 2 emitted from the first surface 150 a of the first prism sheet 150 .
- the light L 2 emitted from the first surface 150 a of the first prism sheet 150 has a third maximum brightness in a third light output direction L 2 a , and an included angle A 4 between the normal direction 110 n of the light output surface 110 a and the third light output direction L 2 a is greater than or equal to 25 and is smaller than or equal to 40 degrees.
- the first prism sheet 150 may change the direction of the chief ray and/or change the direction of the marginal ray. Therefore, compared to the light L 1 emitted from the light output surface 110 a of the light output module 110 , the light L 2 emitted from the first surface 150 a of the first prism sheet 150 may be the light that has smaller viewing angle and has better collimation.
- the first prism structure 151 has a first top corner 151 b , and the angle of the first top corner 151 b is not smaller than 80 degrees and is not greater than 90 degrees, but the invention is not limited thereto.
- an included angle between the first extending direction 151 a and a projection L 1 c of the first light output direction L 1 a on the light output surface 110 a is greater than or equal to 75 degrees.
- the included angle between the first extending direction 151 a and the light incident surface 130 c of the light guide plate 130 is smaller than or equal to 15 degrees, but the invention is not limited thereto.
- the second prism sheet 170 is disposed on the first surface 150 a of the first prism sheet 150 .
- the second prism sheet 170 has a plurality of second prism structures 171 extending in a second extending direction 171 a , the second prism structures 171 face away from the light output module 110 , and the included angle between the first extending direction 151 a and the second extending direction 171 a is not smaller than 0 degrees (such as the first extending direction 151 a and the second extending direction 171 a are parallel to each other) and is not greater than 30 degrees.
- the second prism sheet 170 has a third surface 170 a and a fourth surface 170 b opposite to the third surface 170 a , the second prism structures 171 are located on the third surface 170 a , and the fourth surface 170 b faces the light output surface 110 a of the light output module 110 .
- the second prism sheet 170 is not a reverse prism sheet.
- the light L 2 After entering from the fourth surface 170 b of the second prism sheet 170 , the light L 2 , which is emitted from the first surface 150 a of the first prism sheet 150 , may have changes of the light path within the second prism sheet 170 (such as refraction and/or reflection), so as to form a light L 3 emitted from the third surface 170 a of the second prism sheet 170 .
- the light L 3 emitted from the third surface 170 a of the second prism sheet 170 has a third maximum brightness in a fourth light output direction L 3 a , and an included angle A 5 between the normal direction 110 n of the light output surface 110 a and the fourth light output direction L 3 a is smaller than or equal to 10 degrees.
- the second prism sheet 170 may change the direction of the chief ray and/or change the direction of the marginal ray. Therefore, compared to the light L 2 emitted from the first surface 150 a of the first prism sheet 150 , the light L 3 emitted from the third surface 170 a of the second prism sheet 170 may be the light that has smaller viewing angle and has better collimation.
- the second prism structure 171 has a second top corner 171 b , and the sum of angle of the first top corner 151 b and angle of the second top corner 171 b is between 170 to 200 degrees, but the invention is not limited thereto.
- two adjacent first prism structures 151 have a first pitch D 1 therebetween
- two adjacent second prism structures 171 have a second pitch D 2 therebetween
- the second pitch D 2 is smaller than the first pitch D 1 .
- an included angle between the second extending direction 171 a and a projection L 1 c of the first light output direction L 1 a on the light output surface 110 a is greater than or equal to 75 degrees.
- the included angle between the second extending direction 171 a and the light incident surface 130 c of the light guide plate 130 is smaller than or equal to 15 degrees, but the invention is not limited thereto.
- FIG. 4 is a cross-sectional schematic view of a backlight module according to the second embodiment of the invention.
- a backlight module 200 of the present embodiment and the backlight module 100 of the first embodiment are similar, the differences are that, in the backlight module 200 of the present embodiment, a light guide plate 230 of the light output module 210 has a plurality of micro-structures 231 .
- the micro-structure 231 of the light guide plate 230 is a convex type micro-structure that protrudes outward from the lower surface 230 b .
- the possibility that the bottom surface 230 b of the light guide plate 230 and the reflective sheet 140 are partially attached may be reduced, so as to reduce the interfering phenomenon (such as: Newton's rings) which affects visual efficiency.
- Each of the micro-structures 231 has an illuminated surface 231 a and back surface 231 b , and, compared to the back surface 231 b , the illuminated surface 231 a is farther away from the light incident surface 230 c .
- an included angle A 6 between the illuminated surface 231 a and the bottom surface 230 b (or a virtual surface 230 b ′ extended from the bottom surface 230 b ) is smaller than or equal to 10 degrees.
- the total reflection phenomenon at the light guide plate 230 may be reduced, so that the light L 1 (as shown in FIG. 1A ) emitted from the light output module 210 is focused in the same direction to reduce the included angle A 3 (as shown in FIG. 1A ) between the first light output direction L 1 a (as shown in FIG. 1A ) and the second light output direction L 1 b (as shown in FIG. 1A ).
- FIG. 5 is a cross-sectional schematic view of a backlight module according to the third embodiment of the invention.
- a backlight module 300 of the present embodiment and the backlight module 100 of the first embodiment are similar, the differences are that, in the backlight module 300 of the present embodiment, a light guide plate 330 of the light output module 310 has a plurality of micro-structures 331 .
- the micro-structure 331 of the light guide plate 330 is a concave type micro-structure that inwardly recessed from the lower surface 230 b .
- Each of the micro-structures 331 has an illuminated surface 331 a and a back surface 331 b , and, compared to the illuminated surface 331 a , the back surface 331 b is farther away from the light incident surface 330 c .
- an included angle A 7 between the illuminated surface 331 a and the bottom surface 330 b (or a virtual surface 330 b ′ extended from the bottom surface 330 b ) is smaller than or equal to 10 degrees.
- the total reflection phenomenon at the light guide plate 330 may be reduced, so that the light L 1 (as shown in FIG. 1A ) emitted from the light output module 310 is focused in the same direction to reduce the included angle A 3 (as shown in FIG. 1A ) between the first light output direction L 1 a (as shown in FIG. 1A ) and the second light output direction L 1 b (as shown in FIG. 1A ).
- FIG. 6 is a three dimensional exploded view of a backlight module according to the fourth embodiment of the invention.
- a backlight module 400 of the present embodiment and the backlight module 100 of the first embodiment are similar, the differences are that, in the backlight module 400 of the present embodiment, a top surface 430 a of a light guide plate 430 of a light output module 410 a plurality of strip structures 432 extending along a third extending direction 432 a , and the third extending direction 432 a is parallel to a normal direction of the light incident surface 430 c.
- the strip structures 432 are lenticular microstructure, for example, so that the light L 1 (as shown in FIG. 1A ) emitted from the light output module 410 is focused in the same direction to reduce the included angle A 3 (as shown in FIG. 1A ) between the first light output direction L 1 a (as shown in FIG. 1A ) and the second light output direction L 1 b (as shown in FIG. 1A ).
- FIG. 7 is a three dimensional exploded view of a backlight module according to the fifth embodiment of the invention.
- a backlight module 500 of the present embodiment and the backlight module 100 of the first embodiment are similar, the differences are that, in the backlight module 500 of the present embodiment further includes a first diffusion sheet 560 and a second diffusion sheet 580 .
- the first diffusion sheet 560 is located between the first prism sheet 150 and the second prism sheet 170
- the second diffusion sheet 580 is located on the second prism sheet 170
- the haze value of the second diffusion sheet 580 is greater than the haze value of the first diffusion sheet 580 .
- the haze value of the first diffusion sheet 560 is greater than 30%, and the haze value of the second diffusion sheet 580 is greater than 50%. As a result, the possibility of generating light leakage and/or Moiré pattern may be reduced.
- FIG. 8 is a three dimensional exploded view of a backlight module according to the sixth embodiment of the invention.
- a backlight module 600 of the present embodiment is similar to the backlight module 500 of the fifth embodiment, the differences are that the first prism sheet 550 has a first diffusion layer 552 on a side (such as on the second surface 550 b of the first prism sheet 550 ) opposite to the first prism structures 551 , and the second prism sheet 570 has a second diffusion layer 572 on a side (such as the fourth surface 570 b of the second prism sheet 570 ) opposite to the second prism structures 571 .
- the haze value of the first diffusion layer 552 is smaller than 10%
- the haze value of the second diffusion layer 572 is smaller than 10%.
- the first prism sheet 550 may have the first diffusion layer 552 and the second prism sheet does not include an element similar to a diffusion layer (for example, the second prism sheet is similar to the second prism sheet 170 ).
- the second diffusion layer 570 may have the second diffusion layer 572 and the first prism sheet does not include an element similar to a diffusion layer (for example, the first prism sheet is similar to the first prism sheet 150 ).
- the pixel structure of the present invention can improve the insufficient color saturation and color shift problems of the display screen.
- the following exemplary experiment is used for the purposes of illustration. However, the exemplary experiment does not limit the scope of the invention.
- measuring the total luminous flux per unit solid angle emitted by the light source per unit area can provide a physical quantity that represents how human eye(s) actually feels in response to the light intensity measured from the light source or the light-emitting element.
- the light intensity in different directions is measured by a general optical measuring instrument, so as to simulate the feeling of human eye in response to light intensity in a visual direction.
- FIG. 9 is a schematic view illustrating coordinate in an exemplary experiment of the invention
- FIG. 10A to FIG. 10C are diagrams showing a relationship of light intensities in different visual directions in the exemplary experiment of the invention. It is noteworthy that, in FIG. 9 , the light output module 110 in the first embodiment is used for explanation, but the light output module in the exemplary experiment is not limited thereto. In the description of FIG. 10A to FIG.
- a first projecting direction 910 a is a direction defined by projecting the visual direction 910 of human eye 900 onto the light output surface 110 a (such as xy plane) of the light output module 110
- a second projecting direction 910 b is a direction defined by projecting the visual direction 910 onto a virtual plane (such as yz plane), which is formed by the normal direction 110 n of the light output surface 110 a and the normal direction 130 n of the light incident surface 130 c
- An angle ⁇ is an included angle between the first projecting direction 910 a and the normal direction 130 n of the light incident surface 130 c .
- An angle ⁇ is an included angle between the second projecting direction 910 b and the normal direction 110 n of the light output surface 110 a .
- a center 110 b of the light emitting surface 110 a serves as an origin of the Cartesian coordinate system (such as the xyz Cartesian coordinate system) and the first projecting direction 910 a is located in quadrants of +x, the value of the angle ⁇ will be positive.
- the first projecting direction 910 a is located in quadrants of ⁇ x, the value of the angle ⁇ will be negative.
- the second projecting direction 910 b is located in quadrants of +y, the value of the angle ⁇ is positive.
- the second projecting direction 910 b is located in quadrants of ⁇ y, the value of the angle ⁇ is negative.
- the ordinate is for the normalized light intensities in each exemplary experiment
- the abscissa is for the corresponding values of the angles ⁇ and ⁇
- the relative light intensity curve corresponding to the different angles ⁇ is represented by solid line
- the relative light intensity curve corresponding to the different angles ⁇ is represented by dash line.
- the light intensity relationship in different visual directions 910 of the light L 1 emitted from the light output surface 110 a of the light output module 110 , the light L 2 emitted from the first surface 150 a of the first prism sheet 150 and the light L 3 emitted from the third surface 170 a of the second prism sheet 170 is measured.
- the included angle between the first extending direction 151 a and the light incident surface 130 c of the light guide plate 130 is equal to 0 degree (for example, the included angle between the first extending direction 151 a and the projection L 1 c of the first light output direction L 1 a on the light output surface 110 a is 90 degrees)
- the included angle between the second extending direction 171 a and the light incident surface 130 c of the light guide plate 130 is 0 degree (for example, the included angle between the second extending direction 171 a and the projection L 1 c of the first light output direction L 1 a on the light output surface 110 a is 90 degrees)
- the angle of the first top corner 151 b is between 80 degrees and 90 degrees
- the sum of the angle of the first top corner 151 b and the angle of the second top corner 171 b is between 170 degrees and 200 degrees.
- the light L 2 emitted from the first surface 150 a of the first prism sheet 150 may have smaller FWHM.
- the light L 3 emitted from the third surface 170 a of the second prism sheet 170 may have smaller FWHM.
- the light L 2 emitted from the first surface 150 a of the first prism sheet 150 may have the angle ⁇ closer to 0 degree.
- the third light output direction L 2 a is closer to the normal direction 110 n of the light output surface 110 a .
- the light L 3 emitted from the third surface 170 a of the second prism sheet 170 may have the angle ⁇ closer to 0 degree.
- the fourth light output direction L 3 a is closer to the normal direction 110 n of the light output surface 110 a .
- the backlight module 100 constituted by the light output module 110 , the first prism sheet 150 , and the second prism sheet 170 can improve the collimation of light.
- the backlight module constituted by the light output module, the first prism sheet and the second prism sheet can at least reduce light at large viewing angle and can improve the collimation of light.
- the backlight module has only two prism sheets to reduce light at large viewing angle and to improve the collimation of light. If the backlight module further has other prism sheets, it is possible that there will be no further significant improvement in efficiency of the backlight module. Therefore, based on the results of the exemplary experiment, the best benefit is picked to balance between cost and efficiency of the backlight module.
- the light intensity in different visual directions 910 of the light L 3 emitted from the third surface 170 a of the second prism sheet 170 is measured under the circumstance that the first prism sheet 150 and the second prism sheet 170 have different configuration angles.
- the included angle between the first extending direction 151 a and the light incident surface 130 c of the light guide plate 130 is 0 degree
- the included angle between the second extending direction 171 a and the light incident surface 130 c of the light guide plate 130 is 0 degree.
- the included angle between the first extending direction 151 a and the light incident surface 130 c of the light guide plate 130 is 15 degrees
- the included angle between the second extending direction 171 a and the light incident surface 130 c of the light guide plate 130 is 15 degrees
- the included angle between the first extending direction 151 a and the second extending direction 171 a is equal to 30 degrees.
- the included angle between the first extending direction 151 a and the light incident surface 130 c of the light guide plate 130 is 45 degrees
- the included angle between the second extending direction 171 a and the light incident surface 130 c of the light guide plate 130 is 45 degrees
- the included angle between the first extending direction 151 a and the second extending direction 171 a is equal to 90 degrees.
- the light L 3 emitted from the third surface 170 a of the second prism sheet 170 may have smaller full width at half maximum and have the angle ⁇ closer to 0.
- the backlight module 100 constituted by the light output module 110 , the first prism sheet 150 , and the second prism sheet 170 , the light at large viewing angle is reduced and the collimation of light is improved under the conditions that the included angle between the projection of the first light output direction on the light output surface 110 a and the first extending direction 151 a is smaller than or equal to 15 degrees, the included angle between the projection of the first light output direction on the light output surface 110 a and the second extending direction 171 a is smaller than or equal to 15 degrees, and the included angle between the first extending direction 151 a and the second extending direction 171 a is smaller than or equal to 30 degrees.
- the included angle between the first extending direction of the first prism structure and the second extending direction of the second prism structure is smaller than or equal to 30 degrees, the light at large viewing angle will be reduced and the collimation of light will be improved. Further, if the included angle between the first extending direction and the light incident surface is smaller than or equal to 15 degrees and the included angle between the second extending direction and the light incident surface is smaller than or equal to 15 degrees, the light at large viewing angle will be reduced and the collimation of light will be improved.
- the first prism sheet has a plurality of first prism structures extending in the first extending direction
- the second prism sheet has a plurality of second prism structures extending in the second extending direction
- the angle between the first extending direction and the second extending direction is less than or equal to 30 degrees. Therefore, the backlight module constituted by the light output module, the first prism sheet and the second prism sheet can reduce light at large viewing angle and can improve the collimation of light.
Abstract
Description
D2<D1/2; and
D2=N·D1, wherein N is not an integer.
Claims (19)
D2<D1/2; and
D2=N·D1, wherein N is not an integer.
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TW107108562A TWI657291B (en) | 2018-03-14 | 2018-03-14 | Backlight module |
TW107108562 | 2018-03-14 |
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US20190285949A1 US20190285949A1 (en) | 2019-09-19 |
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Families Citing this family (13)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN109188777A (en) * | 2018-10-31 | 2019-01-11 | 厦门天马微电子有限公司 | A kind of backlight module and display device |
JP2020119678A (en) * | 2019-01-21 | 2020-08-06 | シャープ株式会社 | Lighting apparatus and display device |
US11009645B2 (en) * | 2019-05-29 | 2021-05-18 | Nano Precision Taiwan Limited | Backlight module |
US11460627B2 (en) | 2019-12-17 | 2022-10-04 | Coretronic Corporation | Backlight module |
CN112987395B (en) * | 2019-12-17 | 2024-03-08 | 中强光电股份有限公司 | Backlight module |
TWM606870U (en) * | 2020-01-08 | 2021-01-21 | 奇象光學有限公司 | Uniform light film group and light source module with the same |
CN111736391A (en) * | 2020-08-13 | 2020-10-02 | 业成科技(成都)有限公司 | Optical assembly and display device |
TWI738465B (en) * | 2020-08-14 | 2021-09-01 | 友達光電股份有限公司 | Display device |
CN114488382A (en) | 2020-11-12 | 2022-05-13 | 中强光电股份有限公司 | Backlight module |
TWI762035B (en) * | 2020-11-16 | 2022-04-21 | 友達光電股份有限公司 | Display device |
CN115561932A (en) | 2021-07-02 | 2023-01-03 | 中强光电股份有限公司 | Backlight module and display device |
WO2023102802A1 (en) * | 2021-12-09 | 2023-06-15 | 瑞仪(广州)光电子器件有限公司 | Optical film set, backlight module, and display device |
CN217112978U (en) | 2022-03-07 | 2022-08-02 | 中强光电股份有限公司 | Light source module and display device |
Citations (10)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH07128662A (en) | 1993-11-04 | 1995-05-19 | Kyocera Corp | Liquid crystal display device |
US20050007793A1 (en) * | 2003-06-09 | 2005-01-13 | Mikio Yoshida | Optical device, area light apparatus and display |
CN101644858A (en) | 2008-08-04 | 2010-02-10 | 鸿富锦精密工业(深圳)有限公司 | Direct backlight module |
US20110102710A1 (en) * | 2009-11-03 | 2011-05-05 | Wintek Corporation | Backlight module and display module |
US20110141765A1 (en) | 2009-12-15 | 2011-06-16 | Industrial Technology Research Institute | Planar light source module and optical film |
US20120106195A1 (en) * | 2010-10-29 | 2012-05-03 | Au Optronics Corporation | Backlight Module |
CN102692671A (en) | 2012-06-14 | 2012-09-26 | 深圳市华星光电技术有限公司 | Light guide plate suitable for 3D (three-dimensional) display |
CN104991297A (en) | 2015-07-16 | 2015-10-21 | 宁波东旭成新材料科技有限公司 | Self-repairing brightness enhancement film |
US20160091654A1 (en) * | 2014-09-30 | 2016-03-31 | Lg Display Co., Ltd. | Liquid crystal display apparatus |
US20180292598A1 (en) * | 2017-04-11 | 2018-10-11 | Young Lighting Technology Inc. | Light source module and prism sheet thereof |
Family Cites Families (11)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH10106319A (en) * | 1996-09-30 | 1998-04-24 | Sony Corp | Anisotropic surface light source device and transmissive display device |
JP2004069879A (en) * | 2002-08-05 | 2004-03-04 | Hitachi Ltd | Liquid crystal display device |
KR20080039956A (en) * | 2005-08-31 | 2008-05-07 | 후지필름 가부시키가이샤 | Optical sheet for display unit and manufacturing method thereof |
CN201007769Y (en) * | 2006-09-22 | 2008-01-16 | 台湾奈普光电科技股份有限公司 | Structure improvement of backlight module |
CN201083931Y (en) * | 2007-09-18 | 2008-07-09 | 台湾奈普光电科技股份有限公司 | Backlight module |
JP2010107721A (en) * | 2008-10-30 | 2010-05-13 | Hitachi Displays Ltd | Liquid crystal display device |
KR101700448B1 (en) * | 2009-10-27 | 2017-01-26 | 삼성전자주식회사 | Method and system for managing security in mobile communication system |
KR20130005330A (en) * | 2011-07-06 | 2013-01-16 | 글로텍 주식회사 | Optical film and manufacturing method thereof, liquid cristal display apparatus using the optical film |
US20160054507A1 (en) * | 2013-03-29 | 2016-02-25 | Sharp Kabushiki Kaisha | Lighting device and display device |
JP6647761B2 (en) * | 2015-12-07 | 2020-02-14 | 恵和株式会社 | Top light diffusion sheet and backlight unit |
JP2017208287A (en) * | 2016-05-20 | 2017-11-24 | 大日本印刷株式会社 | Surface light source device and transmission type display device |
-
2018
- 2018-03-14 TW TW107108562A patent/TWI657291B/en active
- 2018-06-08 CN CN201810587334.1A patent/CN108490692B/en active Active
- 2018-06-21 US US16/013,958 patent/US10488708B2/en active Active
Patent Citations (12)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH07128662A (en) | 1993-11-04 | 1995-05-19 | Kyocera Corp | Liquid crystal display device |
US20050007793A1 (en) * | 2003-06-09 | 2005-01-13 | Mikio Yoshida | Optical device, area light apparatus and display |
CN101644858A (en) | 2008-08-04 | 2010-02-10 | 鸿富锦精密工业(深圳)有限公司 | Direct backlight module |
US20110102710A1 (en) * | 2009-11-03 | 2011-05-05 | Wintek Corporation | Backlight module and display module |
US20110141765A1 (en) | 2009-12-15 | 2011-06-16 | Industrial Technology Research Institute | Planar light source module and optical film |
TW201120525A (en) | 2009-12-15 | 2011-06-16 | Ind Tech Res Inst | Planar light source module and optical film |
TWI438531B (en) | 2009-12-15 | 2014-05-21 | Ind Tech Res Inst | Planar light source module and optical film |
US20120106195A1 (en) * | 2010-10-29 | 2012-05-03 | Au Optronics Corporation | Backlight Module |
CN102692671A (en) | 2012-06-14 | 2012-09-26 | 深圳市华星光电技术有限公司 | Light guide plate suitable for 3D (three-dimensional) display |
US20160091654A1 (en) * | 2014-09-30 | 2016-03-31 | Lg Display Co., Ltd. | Liquid crystal display apparatus |
CN104991297A (en) | 2015-07-16 | 2015-10-21 | 宁波东旭成新材料科技有限公司 | Self-repairing brightness enhancement film |
US20180292598A1 (en) * | 2017-04-11 | 2018-10-11 | Young Lighting Technology Inc. | Light source module and prism sheet thereof |
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TWI657291B (en) | 2019-04-21 |
TW201939132A (en) | 2019-10-01 |
CN108490692A (en) | 2018-09-04 |
CN108490692B (en) | 2021-06-04 |
US20190285949A1 (en) | 2019-09-19 |
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